Machine for closing tube ends



Jan. 20, 1948. w. ENGHAUSER I 2,434,737

'MACHINE FOR CLOSING TUBE ENDS Filed Sept. 28, 1943 2 Sheets-Sheet l INVENTOR.

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Jan. 20, 1948. w. ENGHAUSER 2,434,737

MACHINE FOR CLOSING TUBE ENDS Filed Sept. 28, 1945 2 Sheets-Sheet 2 i Z a N J .6 j f INVENTQR. BY

Patented Jan." 20, 1948 MACHINE FOR CLOSING'TUBE ENDS Winford L. Enghauser, to The Production P non, Ohio, a corpora Cincinnati, Ohio, assignor lating Works, Inc., Lebationof Ohio Application September 28, 1943, Serial No.,504 ,137

' 4 Claims.

This invention relates to a machine for form ing closures at the ends of pipes and tubes. The invention is based generally upon the old and Well-known principles of generating heat by friction in the piece being worked upon, and working the piece while the metal thereof is in a more plastic condition thus attained. However, the invention is directed particularly to improvements in the application of this principle especially upon relatively thin wall tubing which does not have the strength to withstand the substantial pressures otherwise necessary to the creation of high frictional heat. The invention also has-been directed particularly to improvements by which the work pieces are left with a better finish, with less wear and galling than heretofore has been possible.

Briefly, the invention contemplates an apparatus wherein the workpiece, while rotating in one direction, is contacted under pressure by a deforming member rotating axially in an opposite direction and pivotally shiftable in a direction laterally to the workpiece for deforming the metal thereof to constitute the closure. Otherwise ex pressed, the invention contemplates an apparatus wherein deforming pressure is applied as a continual wiping action along a shifting or moving peripheral line 'at the end of the workpiece. Simultaneous with the generation of heat through friction the area of contact between the workpiece and deforming member moves through a zone ranging peripherally from the extreme endwise portion of the workpiece to a point spaced marginally inwardly therefrom.

The combination of this shifting movement of the local area of pressure contact plus a rapid rotation of the workpiece and deforming member in opposite directions accomplishes the desired endwise deformation in but a fraction of the time which heretofore has been required, and the extreme degree of heat generated over a small localized area permits the forming of tube walls which would be burned and broken if the temperature were less or the affected area greater. While the reasons which explain this result are not fully understood it is believed that counterrotation of the two members produces, between them, a much higher relative speed than heretofore has been employed, resulting in the development of very high temperatures at the local points of contact, whereby the metal at such points of contact, being much more plastic, easily becomes deformed; closure through deformation of the metal is completed through continual shifting of the location of these local hot spots.

The utility of the improvement in respect to prior apparatuses may be illustrated by the fact that lightweight tubing, for example, tubing having a wall thickness of .022 inch may be closed conveniently and quickly by the present apparatus while end closures cannot be formed on such materials by the apparatuses which heretofore have,

been known, because the tubing is not strong enough to withstand heavy lateral pressures through which suitable heat may be generated.

In the preferred embodiment of the apparatus, a base is provided pivotally to support a rotating deforming shoe. A chuck, power driven for rotation, is mounted axially for pressure engagement ofthe workpiece held therein with the deforming I shoe, but the power drive for the chuck is in a direction opposite that of the power drive of the shoe. An adjustment is provided for moving into pressure contact with the endwise portion of the workpiece, whereby the pressure may be maintained as the deformation proceeds toward completion.

The shoe initially may be a fiat faced member but as one workpiece after another is deformed, the shoe gradually becomes worn to present a slight concavity at its work contacting face and it has, peculiarly, been found that when this condition is reached a somewhat better result is obtained than when the shoe is new and flat; probably the reason is that the local point of contact of a shoe worn to concavity is somewhat larger than the local point of contact, or point of tangency of the original flat surface with the periphery of the workpiece, the greater area of contact resulting in a greater area for heat dissipation whereby deformation takes place more readily.

From these foregoing principles upon which the invention is based and from the following detailed description and drawings which show a preferred embodiment of the machine, those skilled in the art readily will comprehend the various modifications to which the invention is susceptible.

In the drawings:

Figure l is a plan view of the apparatus showing the workpiece held for rotation and the deforming shoe aligned axially with respect to its direction of rotation with the workpiece and ready to be shifted laterally therefrom.

Figure 2 is a side elevation of the apparatus.

Figure 3 is a sectional view through the workpiece and shaft for driving it when the face of the workpiece is new and fiat.

Figure 4 is a view similar to Figure 3 but shows the slight concavity developed in the face of the workpiece after usage thereof.

Figure 5 is a diagrammatic view showing pivotal shifting of the shoe with the workpiece at the beginning of a closing operation.

Figure 6 is a view similar to Figure 5 showing the parts at an intermediate stage in the closing operation, the final appearance of the end of the workpiece being shown in Figure 2.

The apparatus, as shown in the drawings, consists of a table I presenting a flat supporting surface having a pivot stud 2 projecting therefrom. The table may be in the shape of a quadrant having an arcuate edge 3 which is concentric with the stud. A base 4 of the deforming mechanismis bored to receive the stud 2 whereby the entire deforming apparatus may be slid over the surface of the table about the axis of the stud.

Base 4 has dovetail ways 5 projecting from its opposite sidewise edges and a slide 6, grooved to be of similar configuration is slidable upon the base. The base also has a boss I at one end thereof for journalling screw 8 while another portion of the screw is suitably interconnected with the slide 6, whereby rotation of the screw slidably moves the carriage on the base.

A block 9 is mounted on the carriage through screws l and it has pillow members ll extending upwardly from it to seat a quill l2 which rotatably sustains a drive shaft l3 in antifriction bearings M at the endwise portions of the quill. The shaft l3 has pairs of collars ll5 and Iii-46 at the ends of the quill, at least one of these pairs of collars being threaded onto the shaft l3 whereby upon-adjustment thereof the shaft may be held against axial movement. One end of the shaft carries a pulley ll while a drive shoe [8 is keyed thereto as at I9, at the opposite end. A companion pair of pillow blocks 20 is arranged over the quill and through screws 2| may be clamped to the pillows H to hold the quill between them. A motor base 22 is fastened through bolts 23 to the upper fiat edges of the pillows 20 to carry a motor 24. Through a pulley 25 and a belt 26 extending to the pulley H the motor is arranged to drive the shaft 13 and thereby rotate the drive shoe 18. The drive shoe preferably presents a wear resisting face made of Stellite or cemented carbide material.

A chuck 21 is rotatably mounted over the table in vertical alignment with the pivot 2 and at substantially the level of the axis of the shaft l3. This chuck through suitable means is driven in a direction of rotation opposite to that of the shaft I3. The details of the chuck mounting and drive therefor may be conventional and, therefore, are not shown in detail.

Workpiece 28 is held rigidly in the chuck 21. It may be seen that the face of the shoe I8 is brought into pressure engagement with the endwise portion of the workpiece through adjustment of the screw 8. At the start of a closing operation, with the workpiece and deforming shoe set into rotation in opposite directions, the screw is adjusted until a suitable pressure is obtained. The magnitude of this pressure will depend upon the wall thickness of the workpiece, the type of material of which it is made and the speed of rotation between the parts. The best pressure setting may be determined easily for any particular tubing which is to be closed by noting the rate at which heat is generated and th ease with which the piece is formed. It has been found, for example, but not by way of limitation, that good closures are obtained on 1%" tubing having walls .022 inch thick by rotating the deforming 4 shoe at 4000 R. P. M. and the workpiece at 154.0 R. P. M. in an opposite direction, or at an average linear speed of 1500 feet per minute. The linear speed, of course, varies from low, at the extreme end to 9. highest value at the juncture of the end closure with the tubing body.

At the start of operation it is desirable to engage the workpiece while the deforming shoe is pivotally offset from the axis thereof substantially; for example, in the manner shown in Figure 5. With pressure applied through the screw 8, the entire base is shifted back and forth around the end of the workpiece causing it to be deformed. Gradually as the metal is swaged, the screw 8 maybe adjusted to increase or maintain the pressure, this operation being done conveniently by holding the handle on the screw 8, both for the purpose of shifting the head and at the same time gradually rotating the screw.

As previously indicated, the face of the shoe l8 may be flat at the start but becomes worn after a number of pieces have been operated upon to present the concavity indicated generally at 29 in the work engaging surface thereof. This concavity will conform substantially to the radius between the face and the pivotal axis and does not indicate an undesirable condition of wear but rather has been found to promote rapid deformation. A fiat face work shoe is shown at the beginning of operations, though it will be understood that this shoe may be concaved before it is put into use for the first time.

While screw adjustment of the head to provide pressure engagement between the parts ha been disclosed, it is to be understood that a hydraulic piston may be used in place thereof in which event the swaging takes place as rapidly as the plasticity of the metal will permit without laterally rupturing the tubing wall. The shifting of the head exerts a thrust upon the metal of the workpiece which urges the metal laterally of the axis and toward closure of the end. In thi manher a wiping action is obtained which promotes the formation of a smooth finish.

Having described my invention, I claim:

1. A machine for closing the ends of metallic tubing comprising driving means for supporting and rotating the tubing, a tool having a forming face disposed at a right angle to the axis of the tubing, driving means for supporting said tool with its axis of rotation in the same plane as that of the axis of the tubing and with the forming face of the tool at a right angle to the axis of rotation of the tool, a swinging support for the tool driving means, said support being pivotally mounted on an axis at right angles to the axis of the tubing and intersecting the same, and means for moving the support so as to swing the forming face around the end of the tubing in contact therewith for frictionally heating the metal of the tubing and forming the same into an end closure.

2. A machine for closing the end of a metallic tube, comprising means for supporting the tube for rotationabout its axis, a table, a tool base mounted on the table for pivotal movement about an axis at right angles to the axis of rotation of the tube and intersecting said axis, a tool, means for rotatively mounting said tool on said base on an axis disposed in the same plane as the axis of the tube and with the forming face of the tool at a right angle to the axis of rotation of the tool, means for driving said tube and said tool in opposite directions, whereby a pivotal movement of the base swings the tool about the end of the tube, the end of the tool being moved in a curve defining the curvature of the closed end of the tube.

3. A machine for closing the end of a metallic tube comprising means for supporting the tube for rotation about its axis, a table, a tool base mounted on the table for pivotal movement about an axis at right angles to the axis of rotation of the tube and intersecting said axis, a tool, means for rotatively mounting said tool on said base on an axis disposed in the same plane as the axis of the tube and with the forming face of the tool at right angles to the axis of rotation of the tool, whereby a pivotal movement of the base swings the tool about the end of the tube, the end of the tool being moved in a curve defining the curvature of the closed end of the tube, and means for-adjusting the tool so as to move its working face into closer contact with the end of the tubing.

4. In a machine for closing the ends of metallic tubing, driving means for supporting the tubing, a tool having a formin face disposed at right angles to the axis of the tubing, means for rotatively supporting said tool with its axis of rotamounted on an axis at right angles to the axis of the tubing and intersecting the same, and

means for moving the support so as to swing the h an end closure.

forming face around the end of the tubing in contact therewith for frictionally heating the metal of the tubing and forming the same into WINFORD L. ENGHAUSER.

REFERENCES crrsn The following references are of record in the flle of this patent:

UNITED STATES PATENTS Number Name Date 1,939,770 Enghauser Dec. 19, 1933 2,284,210 Johnson May 26, 1942 2,325,522 Lauer July 2'7, 1943 

